Abstract

Background: Although most studies recommended that early surgery for cauda equina syndromes (CES) be performed within

Methods: The 2 major variants of CES include; incomplete/partial ICES, and those with urinary retention/bowel incontinence (RCES). Those with ICES often exhibit varying combinations of motor weakness, sensory loss (i.e. including perineal numbness), and urinary dysfunction, while RCES patients typically exhibit more severe paraparesis, sensory loss including saddle anesthesia, and urinary/bowel incontinence. The pathology responsible for ICES/RCES syndromes may include; acute disc herniations/stenosis, trauma (i.e. including iatrogenic/ surgical hematomas etc.), infections, abscesses, and other pathology. Surgery for either ICES/RCES may include decompressions to multilevel laminectomies/fusions.

Results: Following early surgery, most studies showed that ICES and RCES patients exhibited improvement in motor weakness and sensory loss. However, recovery of sphincter function was more variable, being poorer for RCES patients with preoperative urinary retention/bowel incontinence.

Conclusions: Although early CES surgery was defined in most studies as

Keywords: Cauda Equina Syndrome, Early Diagnosis, Optimal Timing, Surgery, “The Sooner the Better” Surgery

INTRODUCTION

Surgery performed “the sooner the better” for patients with cauda equina syndromes (CES) was best [ Table 1 ].[ 1 , 3 - 18 ] Early surgery for CES was typically defined as within <48 h. after the onset of symptoms/signs; however, the two largest Nationwide Inpatient Sample Database (NISC) series recommend that CES surgery be completed within 0–<24 h. to achieve the best outcomes [ Table 1 ].[ 1 , 4 - 6 , 9 , 10 , 14 , 16 - 18 ] CES syndromes are divided into incomplete/partial CES (ICES) versus complete/retention/incontinence CES (RCES) syndromes based upon the respective lesser or greater severity of preoperative motor, sensory, and/or sphincteric deficits.[ 9 , 16 , 17 ] ICES/RCES syndromes were largely attributed to; acute disc herniations/stenosis, iatrogenic-surgical trauma, trauma/fractures, infections/abscesses, and other factors.[ 1 - 18 ] Early surgery, predominantly including laminectomy to multilevel decompressions with/ without fusions, increased the probability of better outcomes for both ICES and RCES populations.[ 1 , 4 - 6 , 9 , 10 , 14 , 16 - 18 ]

Table 1:

Literature on optimal timing of surgery of Cauda Equina syndromes.

DIFFERENT COMBINATIONS OF PREOPERATIVE SYMPTOMS AND SIGNS OF ICES AND RCES

Multiple studies confirmed that the red flags for CES (i.e. including ICES and RCES syndromes) included; varying severities of sciatica, motor weakness, sensory loss with reduced perineal sensation, bladder/bowel dysfunction/urinary retention, and loss of sexual function [ Table 1 ].[ 1 , 4 - 6 , 9 , 10 , 13 , 14 , 16 - 18 ] ICES patients usually exhibited varying motor weakness, sensory deficits (i.e. perineal numbness), and urinary dysfunction, while RCES patients more typically had paresis/paralysis, more severe sensory loss including saddle anesthesia, and urinary/bowel retention/incontinence.[ 3 , 8 , 13 ] Preoperative symptoms in Barker et al. 61 ICES/RCES patients with acute lumbar disc herniations exhibited; low back pain (67%), perineal numbness (47%), bladder (33% with 10% of these requiring a Foley), and bowel dysfunction (38%).[ 3 ] Postoperatively, Hazelwood et al. (2019) 46 ICES/RCES patients exhibited residual/long-term loss of physical (48% motor/sensory), bladder (76%), bowel (13%), and sexual function (39%), with the worst outcomes seen in RCES patients.[ 8 ]

SURGERY FOR ICES AND RCES SYNDROMES: “THE SOONER THE BETTER” IS BEST

Most smaller studies recommended early surgery for CES (ICES/RCES) within <48 h. [ Table 1 ].[ 1 , 4 , 6 , 10 , 16 - 18 ] However, two of the largest and highest quality NISC series documented that surgery performed from 0-<24 h after the onset of symptoms or performed “the sooner the better”, resulted in the best outcomes [ Table 1 ].[ 1 , 4 , 6 , 10 , 16 , 18 ] In 2017, Thakur et al., using the NISC (2005–2011) database involvling 4066 adults with CES, determined that surgery in ICES patients performed in <24 h. resulted in better outcomes with lower mortality rates, shorter lengths of stay, lesser hospital charges, and a reduced rate of unfavorable discharges versus surgery performed after 48 h [ Table 1 ].[ 17 ] Hogan et al. (2019), based on a National Inpatient Sample Database of 20, 924 CES patients, additionally confirmed that early CES surgery (i.e. performed within 0–<24 h.) resulted in lower complication and mortality rates.[ 10 ] The operations performed in most studies included decompressive laminectomies with occasional decompressions/fusions [ Table 1 ].[ 3 , 7 , 10 , 12 , 13 , 15 , 17 , 18 ]

LONG-TERM POSTOPERATIVE SPHINCTER DYSFUNCTION FOR BOTH ICES AND RCES PATIENTS

Several studies observed greater residual long-term bladder or bowel dysfunction after surgery in both ICES and RCES patients [ Table 1 ].[ 7 , 9 , 12 , 15 ] Gleave et al. (2002) concluded there was no benefit for RCES patients to undergo early emergent surgery as it did not improve the extent of postoperative recovery of sphincter function.[ 7 ] When Heyes et al. (2018) evaluated 45 CESS (suspicious/incomplete), 22 ICES (incomplete), and 69 RCES (urinary retention) patients, those undergoing early surgery (i.e. <24 h) had better sensory/motor outcomes, but early surgery did not favorably impact recovery of sphincter function.[ 9 ] In Lam et al. (2020) they found that for 71 patients with CES undergoing early/emergent surgery, patients exhibited greater postoperative improvement in motor/sensory function. However, they still experienced a “... high prevalence of long-term bowel, bladder, and sexual dysfunction post-CES (surgery).”[ 12 ] Further, at 5 postoperative years in Seidel et al. (2021) 2362 patients with CES versus 9448 matched controls (i.e. from the National Insurance Claims Database), 10–12% of CES patients exhibited residual bladder dysfunction, and required a 0.7–0.9% incidence of additional urological procedures versus control patients.[ 15 ]

MEDICOLEGAL VIEW OF SURGICAL TIMING FOR CES

The medicolegal literature acknowledges that CES surgery performed “the sooner the better” is best [ Table 1 ].[ 5 , 11 , 14 ] Daniels et al. (2012) emphasized that CES remains one of the “true surgical emergencies” that should be addressed <48 h. after the onset of symptoms.[ 5 ] Their evaluation of CES court cases showed a “…positive association between time to surgery >48 h and adverse decisions.” In 2020, Medress et al. noted that the failure to timely diagnose and treat CES was one of the major causes of medical negligence; they recommended early/emergent CES surgery (i.e. <48 h.) to avoid permanent neurological injury.[ 14 ] Kuris et al. (2021) similarly emphasized that MR and/or Myelo-CT studies and decompressive surgery be performed “the sooner the better” in CES patients to improve outcomes.[ 11 ]

CONCLUSION

Although many studies stated that CES surgery should be performed within <48 h. after symptom onset, two of the largest NISC series (i.e. involving 20, 924,[ 10 ] and 4066 patients respectively[ 17 ]) documented that CES surgery performed “the sooner the better” (i.e. 0–<24 h) was best [ Table 1 ].[ 1 , 2 - 18 ]

Declaration of patient consent

Patient’s consent not required as there are no patients in this study.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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